Electric switch



(No Model.)

B. M. HUNTER. ELECTRIC SWITCH.

N0. 462,407. Patented NOV.3,1891.

UNITED STATES PATENT OFFICE.

RUDOLPH M. HUNTER, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE THOMSON-HOUSTON ELECTRIC COMPANY, OF CONNECTICUT.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 462,407, dated November 3, 1891.

Application filed May 22, 1891- Serial No. 393,695. (No model.)

To all whom it may concern.-

Be it known that I, RUDOLPH M. HUNTER, of the city and county of Philadelphia, and State of Pennsylvania, have invented an Improvement in Electric Switches, of which the following is a specification.

My invention has reference to electric switches; and it consists of certain improvements which are fully set forth in the following specification and shown in the accompanying drawings, which form a part thereof.

My invention set out in this application (Case 197) has particular reference to an electric switch designed for breaking electric circuits conveying large currents. The particular object in View is a construction which shall protect the metallic contacts (or those normally relied upon when the circuit is closed) from being burned out upon the act of opening and closing the switch. In accomplishing this I employ secondary fusible cont acts, preferably of carbon, which are last to separate and first to come together in operating the switch, so that the spark is produced between the carbon contacts in place of the metallic contacts. This construction furthermore permits the operation of the switch deliberately and without hurry, the operation of interrupting the current being performed with impunity, so far as the metal portions of the switch are concerned.

An important part of my invention relates to the automatic feeding of the carbon c011- tact to compensate'for wear or consumption which takes place between the points or portions brought into contact upon opening and closing the switch, the said parts being consumed in a manner similar to what takes place in an arc lamp.

My invention will be more fully understood by reference to the accompanying drawings, in which- Figure 1 is a front elevation of a switch embodying myinvention. Fig. 2 is a plan view of same, and Fig. 3 is a cross-section of a portion of the switch on line a: 00 of Fig. 1.

A is the base of the switch, and may be formed of wood, porcelain, or of any suitable insulating material.

B is a pin, upon which is loosely journaled an arm C, carrying upon its free end a carbon-holder P, and a pivoted clamping lever or catch E, which is pressed against the carbon D by the action of the spring F. By moving the lever E when the arm C is raised slightly the carbon D is permitted to fall by gravity, an action which may be assisted by weights or springs, such as are well known in arc-lamp constructions. The arm C is guided against a guide-face K, and its movement is limited by stops 7c- 7.' upon said guide.

G is a bell-crank lever, also pivoted upon the pin B and provided with a handle G, by which it may be operated. This lever G is provided at the top with a weight G which, when turned to the right by the operation of the lever in opening the switch, tends to hold the switch open until the weight is again thrown to the left of a vertical line through the pin 13. The lever G is further provided with a contact-blade g,proj ecting downwardly and adapted to fit the spring-contacts O and O, respectively, secured to or formed on the plates L and P, having the terminal bindingposts Q Q arranged thereon, respectively. The plate L is also provided with a carbon-holder 7, arranged beneath the carbon-holder c, and a carbon N is adapted to be clamped therein by a clamping-screw M. The arm C is further provided with a curved face H, concentrio with the pin B, and this face may be provided with a notch or recess 7L. The lever Gr is provided with a spring I, which runs against the face ll for maintaining contact and also for the purpose of insuring the movement of the arm C with the arm G in a certain predetermined manner. The lever G is also provided with a shoulder S, which strikes the stop ll, secured to the arm C, and also with an arm T, having a projection 25, which operates against the cam-face c of the lever or catch E, for the purpose of tripping the said lever upon the operation of the switch.

R is a'sheet of mica, which is arranged back of the carbon contacts D and N to prevent the heat of the are destroying the base A.

J is a spring, which may be employed, if desired, for the purpose of steadying the arm C and also assisting in creating a friction to prevent its tendency to drop when raised.

The operation of my improved switch will now be understood. The parts being in the position shown in Fig. 1, the movement of the handle G to the left will cause the lever G to oscillate and slightly raise the arm C by the projection 25 striking the cam end 6 of the lever E, at the same time liberating the carbon D and permitting it to rest freely upon the carbon N. A'further movement of the lever G trips the lever E, permitting it to clamp the carbon D, which is pressed against the carbon N by the weight of the arm and its connections. The lever G continues to move, and while the contactsD and N remain closed the knife-contact 9 leaves the spring-contact O and maintains contact with the spring-contact O. The current is now passing from plate L through the carbons N and D, arm 0, spring I, lever G, contact 0', to the plate P, and the separation between the contacts g and 0 took place while this circuit was closed. A further movement of the lever G causes the shoulder S to strike the stop H and separate the contacts D and N, producing an arc. The circuit is broken through this arc, and after the said circuit is broken the contact g separates, if desired, from the contact 0. The weight G2 is then to the right of the pin D, and the switch is maintained in its open position until the handle is again shifted.

Reversing the operation of the switch to close the circuit, we have the arm 0 moved downward by the action of grawty, and the spring I, which is caught into the notch h. The carbon D is brought into contact with the carbon N, producing such are as would result due to the current, and after this contact has been made (which of course takes place subsequent to the closing of the contact between g and O) the contact g comes into. contact with the spring-contact O, producing a metallic circuit after the arc has been formed and extinguished between the contacts D and N. After the contact has been made with O the projection t strikes the cam end 6 of thelever E and liberates the carbon D, permitting it to reset itself. Upon the passage of the projection f the lever-clamp E again grasps the carbon D. By this means we have a positive making and breaking of the circuit between the carbon contacts D and N, and a subsequent closing of metallic contacts for completing the normal condition of the circuit. It is also seen that where large currents are employed the carbon will be consumed more or less rapidly, but this consumption will be compensated for by the employment of the automatic feeding devices which resets the carbons for every operation of the switch. The construction is also one in which the weight of the arm O is positively brought into operation to insure apositive contactbetween the carbons D and N, which is necessary in practice to prevent the sparking with the contact 0.

It is not essential to my invention that the springI and face H be employed; but in practice I find it desirable, as aside from the positive action which it forms between the parts G and O, the spring acts as a circuit for the passage of the current from O to G.

\Vhile I prefer the construction shown, it is evident that the details may be greatly modified to more or less change the general appearance of the switch without in the least altering or modifying the essential features thereof.

Having now described myinvention, what I claim as new, and desire to secure by Letters Patent, is

1. In an electric switch, the combination of metallic contacts for closing the circuit between the terminals, carbon or fusible contacts also for closing the circuit between the terminals, a movable hand-operated part for successively opening the metallic contacts and fusible contacts, and feeding mechanism for automatically feeding the fusible contacts by the normal operation of the switch to compensate for consumption.

2. I11 an electric switch, the combination of metallic contacts, fusible contacts, a circuit common to both sets of contacts and including them in parallel, hand-operated parts for successively separating the metallic contacts and fusible contacts and for successively closing the fusible contacts and metallic contacts, a catch for holding one of the fusible contacts to the hand-operated part, and a projection in the path of the catch for operating it to liberate the fusible contact upon moving it by thehand-operated part, whereby the throw of the hand-operated parts may be substantially the same while permitting for consumption of the fusible contacts.

3. In an electric switch, the combination of metallic contacts and fusible contacts for closing two independent circuits between the terminals of the switch, hand-operated parts for opening and closing the said contacts and moving the metallic contacts a greater distance than the fusible contacts, a catch 'for holding one of the fusible contacts to the hand-operated part, and a projection in the path of the-catch for operating it to liberate the fusible contact upon moving it bythe hand-operated part, whereby the throw of the hand-operated parts may be substantially the same while permitting for consumption of the fusible contacts.

4. In an electric switch, the combination of metallic contacts and fusible contacts for closing two independent circuits between the terminals of the switch, hand-operated parts for opening and closing the. said contacts and moving the metallic contacts a greater distance than the fusible contacts, and a feeding device for feeding one of the fusible contacts operated by the movement of the metallic contact.

5. In an electric switch, the combination of two metallic contacts, two carbon or fusible contacts controlling independent circuits be tween the terminals and one of each of said ICS contacts being connected with one terminal of the switch, a single handy-operated part for operating both' the metallic and carbon or fusible contacts and adapted to maintain the metallic contacts out of contact a longer period of time than the carbon or fusible contacts in the normal operation of the switch, and a spring-contact between the hand-operated part and the other terminal of the switch.

6. In an electric switch, the combination of a stationary metallic contact and a stationary fusible carbon contact connected to one terminal, a movable metallic contact for operating in connection with the stationary metallic contact, amovable holder having a fusible or carbon contactfor operating in connection with the stationary fusible or carbon con- .tact, automatic devices for feeding the caran electrical connection between the otherterminal of the switch and the movable metallic and fusible contacts.

'7. In an electric switch, the combination of a stationary metallic contact and a stationary fusible carbon contact connected to one terminal, a movable metallic contact for operating in connection with the stationary metallic contact, a movable fusible or carbon contact for operating in connection with the stationaryfusible or carbon contact, a handle for operating the movable metallic contact, a sliding connection between the movable metallic contact and the movable fusible or carbon contact, whereby the former is moved to open the metallic contacts and then act upon the fusible or carbon contact to move it from the stationary fusible or carbon contact, a

feeding device for the fusible contact operated by the movable metallic contact prior to its moving the movable fusible or carbon contact, and an electrical connection between the other terminal of the switch and thc movable metallic and fusible contact.

8. In an electric switch, the combination of stationary carbon contacts and metallic contacts for controlling a circuit leading from one of the terminals of the switch to the other terminal of the switch, a pivoted holder for one of the carbon contacts, a hand-operated pivoted holder for one of the metallic contacts provided with a handle to operate the same, a connecting mechanism between the pivoted holders, whereby the metallic contacts are entirely separated before the carbon contacts leading to the same terminals are separated,

and a catch carried by the pivoted holder for V the metallic contact for positively forcing the movable fusible contact against the stationary fusible contact.

9. In an electric switch, the combination of carbon contacts and metallic contacts for controlling a circuit leading from one of the terminals of the switch to the other terminals of the switch, a pivoted holder for one of the carbon contacts, a pivoted holder for one of the metallic contacts provided with a handle to operate the same, connecting mechanism between the pivoted holders, whereby the metallic contacts are entirely separated before the carbon contacts leading to the same terminal are separated, a clamp for the movable carbon carried by the pivoted holder, and operating mechanism therefor connected with the pivoted holder of the metallic contact.

In testimony of which invention I have hereunto set my hand.

R. M. HUNTER.

Witnesses:

ERNEST HOWARD HUNTER, S. T. YERKES. 

